Buttonhole-clamp.



A. BOYD.

BUTTONHOLE CLAMP.

APPLICATION FILED MAY-13, 1912.

1,087,569. Patented Feb. 17,1914,

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' WITNESSES: Y //v VENTOR ATTORNEY COLUMBIA PLANOORAPH (10.. WASHINGTON, D. C.

A. BOYD.

BUTTONHQLE CLAMP. APPLIOA'I'ION FILED-MAY 13, 1912.

1,087,569. Patented Feb; 17, 914.

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mm... 4 un"...

WITN88E8: INVENTOR ALEXANDER BOYD, OF ELIZABETH, NEW JERSEY, ASSIGNOR TO THE SINGER MANUFACTURING COMPANY, A CORPORATION OF NEW JERSEY.

BUTTONHOLE-CLAMP.

memes.

Specification of Letters Patent.

Patented Feb. 17, 1914.

Application filed May 13, 1912. Serial No 696,825.

To all whom it may concern Be it known that I, ALEXANDER BOYD, a citizen of the United States, residing at Elizabeth, in the county of Union and State of New Jersey, have invented certain new and useful Improvements in Buttonhole- C'lamps, of which the following is a specification, reference being had therein to the accompanying drawings.

This invention has for its object; to provide ample clearance, in a work-holder for buttonhole sewing machines, in the connection between the upper and lower clamping members to accommodate the various articles, such as the bosoms of shirts and collars and cuffs, to which the buttonholes are to be applied.

According to the present improvement, the work-holder is constructed with a baseplate sustaining the foot-plate of a fulcrumblock provided with a fulcrum-pin for the clamp-arm carrying the upper member of the work-clamp and having a rigid arm spaced above the base-plate and carrying a post having a shoulder between which and the clamp-arm is interposed a spring by means of which the upper-clamping member is pressed upon the lower clamping member sustained by the base-plate. The footplate of the fulcrum-block is preferably secured adjustably upon the base-plate, so that the position of the upper clamping member may be shifted in adjusting the machine for different sized buttonholes without disturbing the adjustment of the pressure spring or the relative positions of the parts connected to or cooperating with the clamp-arm.

In the accompanying drawings, Figure 1 is a plan of a work-holder embodying the present improvement, Fig. 2 a side elevation and Fig. 3 a front elevation of the same. Fig. 4 is a perspective View of the fulcrumblock and the spring-supporting post sustained thereby.

As represented substantially in the United States patent of E. E. Allen, No. 785,146, of March 21, 1905, the work-holder is constructed with the cross slide-plate 1 formed with a transverse slideway 2 upon which is secured by means of the screws 3 the throatplate 4 formed with the needle-aperture 5 and knife-slot 6. To the slideway 2 is fitted the longitudinal slide-plate 7 having the elongated aperture 8 embracing the throat depending bearing lug 17 at the forward end of the clamp-arm 18. The rearward end of the clamp-arm is fitted within and secured upon a seat formed in the top of the rocking block 19 having the depending apertured ears 20 entered by the fulcrum-pin 21 secured from endwise movement by means of the set-screw 22 within alined apertures in the forked block 23 rising from the footplate 24 sustained by the base-plate sec tion 9.

The fulcrum-block 23 has a forwardly ex tending rigid arm or extension 25 in the extremity of which is secured the upwardly extending post 26 with threaded upper portion 26 adapted to receive the shouldered thrust-nut 27. Loosely mounted upon the post 26 is the sleeve 28 having at the lower end a substantially triangular flange 29 in which are secured two blunt-pointed bearing studs 30 by means of suitable lock-nuts 31 applied to their shanks, and a centering stud 32 depending through an aperture in the clamp-arm 18 and entering an aperture 25 of the arm 25, the stud 32 being secured against turning by means of the lock-nut 33. Interposed between the knurled flange of the nut 27 and the flange 29 of the sleeve 28 is the pressure spring 34 which acts through the studs 30 to press the upper-clamping member upon the throat-plate 4. Secured upon the rearward end of the clamp-arm 18 by means of the screws 35 is the overlapping forward end of the rigid clamp-lifting arm 36 by means of which the clamp-arm 18 may be tilted upon its fulcrum-pin 21 in opposition to the spring 34 to open the workholder.

The edges of the foot-plate 24 are fitted within a guideway formed by the adjacent edges of the spaced strips 37 and 38 secured upon the base-plate member 9, by means of screws 39 and 40. The foot-plate 24 of the fulcrum-block is formed with a series of longitudinal slots .1 entered by the shanks of the ela1np-screws i2 tapped into the baseplate section 9 and having washers 48 interposed between their heads and the plate 2%. The tuicrum-blocl: 23 is thus secured adjustahly within the guideway of the baseplate.

13y loosening the screws 42, the fulcrum block and the several parts which it carries may be shil d bodily for changing the position of the clamping foot 12 relative to the throat-plate -l without disturbing the adjustment of the spring pressure upon the clamping arm 18, so that, after the thrustnut is once adjusted upon the post 26 to secure the requisite pressure of the clamping foot for a certain line of work, this adjustment may be maintained while the machine is adapted for applying buttonholes of different lengths.

According to the present improvement, the fulcrum-block is ofi'set a considerable distance from alinement with the stitching position, both longitudinally and laterally, and as the spring-supporting post 26 is sustained by the same materially above the baseplate of the work-holder, it will be observed that ample clearance is provided beneath the same to receive a large portion of a garment, such as a shirt, at either side of the position in which the buttonhole is to be located.

Having thus set forth the nature of the invention, what I claim herein is 1. In a work-holder, in combination, a base-plate provided with a lower clamping member, a fulcrum-block sustained thereon in a position ofl'set both longitudinally and laterally from the stitching point and carrying a fulcrunrpin and formed with a forwardly extending rigid arm overhanging and spaced from the base-plate, a clamparm pivotally mounted upon said fulcrumpin and carrying the upper clamping memher, a spring-supporting post sustained by said arm of the fulcrum-block and provided with a shoulder, and a pressure spring surrounding said spring-supporting post and interposed between the shoulder thereof and said clamp-arm.

2. In a worleholder, in combination, a base-plate provided with a lower clamping member and with a longitudinal guideway, a fulcrum-block having a foot-plate fitted within said guideway and carrying a fulcrum-pin and formed with a forwardly extending rigid arm overhanging and spaced from the base-plate, means for adjustably securing the foot-plate of said fulcrumblock within the guideway of said baseplate, a clamp-arm pivotally mounted upon said fulcrum-pin and carrying the upper clamping member, a spring-supporting post sustained by said arm of the fulcrum-block and provided with a shoulder, and a pressure spring surrounding said spring-supporting post and interposed bet-ween the shoulder thereof and said clamp-arm.

In testimony whereof, I have signed my name to this specification, in the presence of two subscribing Witnesses.

ALEXANDER BOYD.

\Vitnesses E. L. ToLLns, H. J. MILLER.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents, Washington, D. G. 

